Transponder devices such as a coil-on-chip RFID device can contain all their functional elements within a single integrated circuit chip. Power to the device is provided by radio frequency transmission, which is picked up by the antenna coil and energises the chip to provide signal. Such devices can be very complex and work at very high speed, generating tens of milliwatts of heat that needs to be dissipated. This is sufficient to cause chip temperatures to rise at rates exceeding 200° C./sec to temperatures greater than 100° C. Thermal stresses from such temperature rises and such high temperatures may affect device performance—they can cause reliability problems and render the device temporarily inoperative.
Conventional integrated circuits are capable of dissipating heat in these quantities when mounted in packages (such as a conventional DIL package). This is not a preferred option for a coil-on-chip RFID device: there is no need to connect to a power source or any other electrical component, and it is desirable to use form factors (such as low profile mounting on a printed page) inconsistent with conventional chip packaging technologies. It is thus desirable to find a solution to the problem of heat dissipation which allows for versatile and effective use of such devices.